1. Field of the Invention
The present invention relates to a storage control system having a storage controller connected to a host computer and which performs the communication of stored data with such host computer.
2. Description of the Related Art
For instance, with a database system that handles enormous amounts of data such as in a data center, data is managed with a storage control system configured separately from a host computer. This storage control system, for example, is configured by having a disk array device. A disk array device is configured by arranging numerous storage devices in an array and, for instance, is created based on RAID (Redundant Array of Independent Inexpensive Disks). At least one or more logical volumes, which are logical storage areas, are formed on the physical storage area provided by a logical storage device group, and this logical volume is provided to the host computer (more specifically, to a program of a database or the like operating on the host computer) as the host system. By transmitting a prescribed command to the disk array device, the host computer is able to write and read data into and from the logical volume.
In this type of storage control system, data destroyed due to the occurrence of failures during the execution of processing is restored at high speed from the backup data. For example, the disk array device described in Japanese Patent Laid-Open Publication No. 2001-216185 is configured as described below in order to restore data. The host issues a pair formation request and pair division request to the disk array device and, after creating a snapshot of the volume, starts the processing. A disk subsystem stores the position of the data renewed after the creation of the snapshot as difference information. Upon receiving the data restoration request from the host, the disk array device restores the data from its renewed location from the snapshot based on such difference information.